This invention relates to the storage of spent fuel from a nuclear reactor and, more particularly relates to the on-site storage of the fuel in a storage area within a concrete cask preliminary to transfer of the fuel to a shipping cask for shipping off site. The concrete cask can be manufactured at the storage site and then reused, after the fuel is shipped, or destroyed and the remaining concrete used for fill or other purposes.
One of the ongoing problems at nuclear reactors is to store the spent fuel that is taken from the reactor. In all cases, the fuel is initially placed into a spent-fuel pool where the water in the pool acts as a radiation barrier for the fuel elements at the bottom of the pool. At some point, however, the fuel must be moved from the pool to permanent disposal in a repository, since, eventually, the pool will become filled with spent fuel. In the United States, the U.S. Department of Energy is responsible, under the Nuclear Waste Policy Act of 1982, to provide for a permanent disposal repository. It will be several years between the time that the fuel is placed in the pool and the time that it is capable of being transferred for disposal, either because it has not yet lost a sufficient amount of radioactivity to be considered safe and economical for transport, or because there is no permanent disposal facility available. The U.S. Department of Energy may temporarily store spent fuel in a Monitored Retrievable Storage (MRS) facility, if it is approved by Congress, but the earliest date for receiving fuel from the reactors is ten to fifteen years away.
It is, therefore, an object of the present invention to provide an intermediate storage of the spent fuel between the pool and the disposal repository or MRS and to provide such a storage area on site at the reactor complex. It is a further object of this invention to provide a storage system in which the storage containers are reusable or can be expendable, if so desired. It is a further object of this invention to provide such a storage container that is mechanically sound and that also provides a sufficient radiation and contamination barrier for the spent fuel.